David's 2001 Pontiac Firebird Formula

David brought us his car to work on while he was overseas. The plan was to build a 67mm turbo kit for the stock engine with a goal of 525rwhp. He also wanted us to rebuild the broken T-56 transmission, and install a Spec Stage 4 clutch.

Engine: 347ci LS1 w/Diamond Pistons, Callies Rods, and Stock GM crank
Management: Stock PCM w/Custom Operating System-2bar Speed Density
Clutch: Spec Stage 4
Transmission: Upgraded T-56, Steel 3-4 Fork, and new Carbon Synchros
Turbo: Precision 67GTS
Wastegate: Tial 38mm
Blow Off Valve: Tial 50mm
Intercooler: 3" Fast Track Performance Intercooler

Engine Work

David wasn't 100% sure about the current modifications to the car. However, we could tell that it did have a decent sized camshaft, headers, and tuning. So we decided to strap it down to the dyno and see what it made to the wheels. We saw that the car did not make very good power, so we decided to take a look inside the engine before turboing it. We found several broken valvesprings, and after pulling the heads we saw a couple of the bores were scratched up as well. We relayed the message to David, and he decided to have us forge the engine.

We kept the stock crank, and added Diamond 2cc relief pistons, Callies rods, and ACL coated bearings, ported and shimmed GM LS6 oil pump, Rollmaster double roller timing chain, and put a stock camshaft back in. We reused the stock heads with a set of Comp 918 springs.

Turbo Kit

Here are a couple pics of a 6.0L turbo kit made to fit around a stock sway bar. The exhaust is about 4-5 feet long, and does a turn downwards near the transmission.

Finished Pictures

Here you can see the exterior of the nearly finished product. David's car was done about 3 years ago when we did little or no media documentation of our work, so we apologize for the lack of photos for David's car.


David's car made these numbers at 14psi using pump gas on a Mustang Dyno. The tuning work was done by another local shop at the time.